A combination of photon and electron radiation therapy (RT) fields was devised to treat patients with initial or recurrent breast cancer presentations which extensively involved the chest wall (CW) and/or the axilla. The ipsilateral supraclavicular, infraclavicular, axillary, and lateral CW regions are treated in continuity by anterior and posterior opposed photon beam "reverse hockey stick" fields. The internal mammary and medial chest wall regions are treated by an anterior electron beam field which is tightly junctioned to the photon beam fields. Electron beam energy and thickness of applied bolus are selected so that the electron beam 80% depth isodose curve matches the anterior pleural surface and/or deepest extent of tumor. The goal of treatment is to deliver 4400-5000 cGy to regions at risk of microscopic tumor with local boosts to 6000-7500 cGy to sites of gross disease. Between January 1977, and June 1985, this technique was selectively used in 46 patients, 31 patients with loco-regional tumor recurrence and 15 post-mastectomy patients who initially presented with locally advanced disease. A minimum tumor dose of 4400 cGy was delivered in all except five patients. A diffuse moist skin reaction developed in 31 of the 44 (70%) patients who received at least 3800 cGy. This healed in less than 1 month in all except seven. Frequency of CW diffuse moist skin reaction within the electron beam field was related to the daily applied RT dose. Diffuse moist skin reactions were also noted to be more frequent among patients who had received prior or concurrent Adriamycin. Significant complications included symptomatic arm lymphedema in seven; CW ulcer in two; and acute radiation pneumonitis; steroid-withdrawal radiation pneumonitis, pleuritis, and marked thrombocytopenia in one patient each. With a follow-up of 36-100 months, there was no evidence of loco-regional tumor relapse in 55% of patients treated for recurrent disease and in 73% treated following mastectomy for locally advanced presentations. In summary, we find the reverse hockey stick technique to be a simple, highly reproducible and effective RT approach for postmastectomy breast cancer patients with extensive initial presentation or recurrent disease.